As a writer, you’re bound to refer to dictionaries pretty often. Would free access to the Oxford English Dictionary online be useful to you?
The world moves fast, and words are no exception. It’s not always easy to keep up with new meanings or spellings. I love having a selection of dictionaries on my shelf, but I wouldn’t be without my access to the OED online, which is kept current by quarterly updates.
Annual subscriptions are £100, but you can have FREE access if your local library subscribes, and most of them do. Many also offer remote access, so you can sign in from home, the coffee shop, or wherever you happen to be writing! To check, just go to www.oed.com, click ‘Sign in’ and enter your library card number in the ‘Library account’ section.
The main OED site provides more than just definitions; it includes a rich history of each word, demonstrating the different spellings that have been used over time.
If you’re after a more simple reference for quick checks, you can also log in to https://premium.oxforddictionaries.com. This site gives you access to a selection of dictionaries, thesauruses and style guides. I just used it to check the plural of thesaurus 
(It can be thesauri too!)
And if you don’t have a library card, this could be the time to get one. That’s free too!